At least four people were killed and 33 others injured when a bomb exploded near a police vehicle in Pakistan's Northwest Charsadda district on Tuesday morning, local media reported. Urdu TV channel Abb Takk reported the bomb targeting the police vehicle exploded at about 7:40 am (local time) at Nowshera road of Charsadda, a district located in the country's Northwest Khyber Pakhtunkhwa province, Xinhua reported. Police said that a large number of people were injured in the attack as the Nowshera road passes through a busy market area, and there were many people including women and kids in the market when the blast happened. Deputy Police Officer Shafi Ullah said that the bomb was triggered off by a remote controlled device and the explosives were fixed in a motorbike parked at the road side. The bomb was detonated when the police vehicle carrying some 13 personnel passed near the motorbike. The injured people, including 11 policemen, three children and two women were shifted to district hospital Charsadda from where 10 critically wounded victims were referred to Lady Reading Hospital Peshawar for better medical treatment. Several nearby shops were destroyed in the blast. No group has claimed responsibility for the attack yet. Police cordoned off the area and kicked off search operation. This is the second attack on police vehicle in the province over the last 10 hours. In an earlier attack on late Monday night, six people including five policemen were killed and four others injured when unknown gunmen opened fire at police vehicle in Peshawar city.